Loop Parallelization and Vectorization

Combining the -parallel and -x{K|W|N|B|P} options instructs the compiler
to attempt both automatic loop parallelization and automatic loop vectorization
in the same compilation. In most cases, the compiler will consider outermost
loops for parallelization and innermost loops for vectorization. If deemed
profitable, however, the compiler may even apply loop parallelization
and vectorization to the same loop. See Guidelines
for Effective Auto-parallelization Usage and Vectorization
Key Programming Guidelines.

Note that in some rare cases successful loop parallelization (either
automatically or by means of OpenMP* directives) may affect the messages
reported by the compiler for a non-vectorizable loop in a non-intuitive
way.